Removal of particulate contamination from the surface of a web is important in many applications, such as cleaning exposed photographic film used in film projection systems, or in the manufacturing of photographic film and the like. Systems for removing particulate contamination from a web surface are well known. For example, air knives and suction cleaning systems are used for this purpose. Particle transfer rollers have proven to be particularly effective in removing particles from web surfaces. A particle transfer roller typically has an adhesive or tacky surface to which particles from the web surface adhere upon contact. A problem with particle transfer rollers, however, is that the cleaning effectiveness of the roller deteriorates as the particles accumulate on the roller surface.
U.S. Pat. No. 4,982,469 describes a sheet surface cleaning apparatus comprising a rotatable dust removing roll having a sticky surface. The apparatus includes a roll cleaning device formed of a flexible porous cleaning pad contactable with the dust removing roll for cleaning the sticky surface. A disadvantage of this device is that the effectiveness of the cleaning pad can deteriorate as particles accumulate on its surface, requiring frequent maintenance shutdown of the apparatus for replacement of the cleaning pad.
U.S. Pat. No. 3,861,861 describes a cleaning apparatus comprising a conformable roll having a sleeve for electrostatically cleaning paper and toner contaminants from a copier fuser roll. A wiper pad of wool or dacron is provided for removing the contaminants from the sleeve. A disadvantage is that no means is provided for cleaning the contaminants that build up on the wiper pad itself, reducing the effective cleaning life of the wiper pad and its cleaning efficiency.
U.S. Pat. No. 2,937,390 describes an apparatus for renewing the tacky surface of a gelatin particle transfer roller comprising a trough containing a plasticizer that is wicked onto the surface of the roller. A disadvantage of the apparatus is that it is not a suitable system for renewing a nongelatin particle transfer roller.
It is an object of the invention to provide a particle transfer roller apparatus and method employing a roller cleaning system with an increased cleaning capability requiring less maintenance. It is also an object of the invention to provide a particle transfer roller renewal apparatus with an extended useable life.